how to determine align to grid parameters faster.

[ken henry]

I'm trying to streamline my workprocess.  I have panaromas that need to align to grid because they contain some frames with pure sky.  To get good alignments i need align to grid parameters for vert and horizonal overlap and roll angle.  I compute the overlaps buy doing a regular alignment on 4 overlaping pictures with lots of control points, then compute overlap based on the size of the single image compared to the that test panaorama.   to get a roll angle, I load on picture into a drawing packaging and since i have some tall buildings, i measure by how many pixels the vertical line is off and do some trig to get the values.  It just takes a minute or so to do those calcs, but I'd like to get around it somehow.  is there a way to get the values directly from the test panaroma that I did?  one problem is the pilot doesn't fix the roll problem completely, it will tilt the panaroma more than I want.  this problem seems like a common one others would have when aligning to grid.

[John Houghton]

Ken, To get the roll value, you can use the fact that the roll value should be the same for all of the images.  On the Advanced page of the Optimizer, check the "Link roll" box near the bottom of the page.  This will keep all the roll parameters the same by optimizing them as a group.  It should level the panorama image with respect to the vertical axis of rotation.   Do this for a row of images and get the roll parameter from the Image Parameter tab.  

John

[ken henry]

You are right, its something i only need to calculate a few times, probably each time i change the lens so camera mount is off.

anyway, i did it your way, but it wants to keep the first image unlocked then lock the remaining ones together.  when it does the alignment and calculates the rolls, the first one is different than the rest, they are all lower than the value i calculated, and the image still slopes on one side.  I suspect the only way to fix it is to give it a reference vertical line.   

For now I'm happy enough with these parts of my procedures.  i've found a few places to speed things up.

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[John Houghton]

On Saturday, November 1, 2025 at 11:45:06 PM UTC ken henry wrote:

i did it your way, but it wants to keep the first image unlocked then lock the remaining ones together.  when it does the alignment and calculates the rolls, the first one is different than the rest, they are all lower than the value i calculated, and the image still slopes on one side.

Ken, When you are levelling a single row of images, in addition to checking the link roll option, you would need to optimize y,p,r on all images, except leave y unchecked for the anchor image.   I just tried it and it certainly works perfectly here.  All the roll parameters were identical.  However, if there are any orphan images (i.e.with no control points), their roll values will remain unaltered.  (I don't know why). So you cannot link roll for all images in a complete panorama when there are orphan sky images.  The suggestion of doing this procedure for a single row of images was just intended to evaluate the correct roll parameters for Align to Grid.

John

[ken henry]

ok, i had all checkmarks except y for anchor.  this time i got all the same for roll.  but,  the images seem to be over rotated, image goes uphill to the right and roll number is higher than the one i can calculate manually from a sharp vertical line in my picture. 

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[John Houghton]

Ken, The complete panorama can and should be levelled using vertical line control points on reliable vertical features.  Linking roll only levels with respect to the vertical axis of rotation.  The vertical axis probably wasn't precisely vertical, so when the final image is properly levelled, the roll values will no longer be the same.

John